This invention relates to hand crimping tools.
Such tools are used to attach terminals and connectors of a wide variety of sizes and shapes to electrical cables. The purpose of the tool is to ensure that the connector or terminal, is in proper electrical contact with the conductive element of the electrical cable.
Hand crimping tools and other crimping tools usually comprise a fixed and a moveable anvil or mandrel, on which the fixed and moveable parts of a crimping die can be mounted. The crimping dies are interchangeable in the tool so that a range of terminals and connectors of different sizes and shapes can be crimped using the same crimping tool.
In order to ensure that sufficient load is applied to the terminal or connector through the crimping die, it is important to control the movement of the moveable mandrel so that the moveable mandrel moves through sufficient distance to apply the necessary load, before the moveable mandrel can be released. Usually this movement is controlled by a ratchet and pawl mechanism, and the mechanism is only released by applying a load to the handle of the tool which is applying the movement to the moveable mandrel.
It has been found that applying the necessary load to the tool in order to disengage the pawl from the ratchet creates considerable stress on components of the tool which in turn reduces the force required to release the pawl from the ratchet during the crimping operation.
Usually, the lever which is applying the load to the moveable mandrel is connected to the moveable mandrel by one or more links, and the moveable mandrel is located in a guide, so that it can only move in a straight line. The links are connected to one another and to the lever and moveable mandrel by pivot pins, and it has been found that due to the loads applied during the crimping cycle and during the ratchet release movement, considerable wear occurs between the pins and links, creating a slackness in the operating mechanism. After a while, because of the slackness which has accumulated, it becomes progressively more difficult to apply the correct loads to the connectors and terminals, resulting in terminals and connectors not being crimped to the necessary standards.